Laundry treating appliance and method of operation

ABSTRACT

A laundry treating appliance and method of operating a laundry treating appliance that includes wetting the laundry load in a drum according to a selected cycle of operation and determining a magnitude of imbalance of the wetted laundry load. A controller of the laundry treating appliance is configured to determine a first extraction speed for rotating the drum based on the magnitude of imbalance.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a divisional of U.S. patent application Ser. No.15/606,210, filed May 26, 2017, now allowed, which is incorporatedherein by reference in its entirety.

BACKGROUND

Laundry treating appliances, such as clothes washers, clothes dryers,refreshers, and non-aqueous systems, may have a configuration based on arotating drum that defines a treating chamber in which laundry items areplaced for treating according to one or more cycles of operation. One ormore of the cycles of operation may include rotating the drum at highspeeds during a spin or water extraction phase to extract liquid fromthe laundry items. If a sufficiently large enough load imbalance ispresent, the laundry treating appliance may experience undesirablevibrations and movements when the drum is rotated at high speeds duringthe spin phase. If the drum rotation speed during the spin phase is toolow, the spin phase may take too long to complete or the desired amountof liquid may not be extracted.

BRIEF DESCRIPTION

In one aspect the present disclosure relates to a laundry treatingappliance, including a drum at least partially defining a treatingchamber for receiving a laundry load for treatment according to a cycleof operation and rotatable about an axis of rotation, a liquid supplysystem fluidly coupled with the treating chamber for supplying liquid tothe laundry load to wet the laundry load according to at least one of awash phase or a rinse phase of a selected cycle of operation, a motoroperably coupled with the drum and configured to rotate the drumaccording to the cycle of operation, and a controller operably coupledto the motor and configured to control the motor to rotate the drum, thecontroller configured to determine a magnitude of imbalance of thewetted laundry load, provide the magnitude of imbalance as input into analgorithm, comprising at least one non-linear polynomial function thatprovides an output indicative of a first extraction speed to thealgorithm based on the input, and control the motor to rotate the drumat the first extraction speed to extract at least a portion of theliquid carried by the wetted laundry load.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic view of a laundry treating appliance in the formof a washing machine.

FIG. 2 is a schematic of a control system of the laundry treatingappliance of FIG. 1 according to an aspect of the present disclosure.

FIG. 3 is a flow chart illustrating a method of operating the laundrytreating appliance according to an aspect of the present disclosure.

FIG. 4 is a graph representative of a speed of rotation of a laundrydrum as a function of an imbalance magnitude of the laundry loadaccording to an aspect of the present disclosure.

FIG. 5 is a graph representative of a speed of rotation of a laundrydrum as a function of an imbalance magnitude of the laundry loadaccording to an aspect of the present disclosure.

FIG. 6 is a flow chart illustrating a method of operating the laundrytreating appliance according to an aspect of the present disclosure.

FIG. 7 is a flow chart illustrating a method of operating the laundrytreating appliance according to an aspect of the present disclosure.

DETAILED DESCRIPTION

FIG. 1 is a schematic view of a laundry treating appliance according toan aspect of the present disclosure. The laundry treating appliance maybe any appliance which performs an automatic cycle of operation to cleanor otherwise treat items placed in a container therein, non-limitingexamples of which include a horizontal or vertical axis clothes washeror washing machine; a combination washing machine and dryer; adispensing dryer; a tumbling or stationary refreshing/revitalizingmachine; an extractor; a non-aqueous washing apparatus; and arevitalizing machine. The laundry treating appliance may be a householdappliance or a commercial appliance.

As used herein, the term “vertical-axis” washing machine refers to awashing machine having a rotatable drum that rotates about a generallyvertical axis relative to a surface that supports the washing machine.However, the rotational axis need not be perfectly vertical to thesurface. The drum may rotate about an axis inclined relative to thevertical axis, with fifteen degrees of inclination being one example ofthe inclination. Similar to the vertical axis washing machine, the term“horizontal-axis” washing machine refers to a washing machine having arotatable drum that rotates about a generally horizontal axis relativeto a surface that supports the washing machine. The drum may rotateabout the axis inclined relative to the horizontal axis, with fifteendegrees of inclination being one example of the inclination.

The laundry treating appliance of FIG. 1 is illustrated as ahorizontal-axis washing machine 10, which may include a structuralsupport system including a cabinet 12 which defines a housing withinwhich a laundry holding system resides. The cabinet 12 may be a housinghaving a chassis and/or a frame, defining an interior enclosingcomponents typically found in a conventional washing machine, such asmotors, pumps, fluid lines, controls, sensors, transducers, and thelike. Such components will not be described further herein except asnecessary for a complete understanding of the invention.

The laundry holding system includes a tub 14 supported within thecabinet 12 by a suitable suspension system and a drum 16 provided withinthe tub 14, the drum 16 defining at least a portion of a laundrytreating chamber 18 for receiving a laundry load for treatment. The drum16 may include a plurality of perforations 20 such that liquid may flowbetween the tub 14 and the drum 16 through the perforations 20. Aplurality of baffles 22 may be disposed on an inner surface of the drum16 to lift the laundry load received in the treating chamber 18 whilethe drum 16 rotates. It may also be within the scope of the presentdisclosure for the laundry holding system to include only a tub with thetub defining the laundry treating chamber.

The laundry holding system may further include a door 24 which may bemovably mounted to the cabinet 12 to selectively close both the tub 14and the drum 16. A bellows 26 may couple an open face of the tub 14 withthe cabinet 12, with the door 24 sealing against the bellows 26 when thedoor 24 closes the tub 14. The washing machine 10 may further include asuspension system 28 for dynamically suspending the laundry holdingsystem within the structural support system.

The washing machine 10 may optionally include at least one balance ring38 containing a balancing material moveable within the balance ring 38to counterbalance an imbalance that may be caused by laundry in thetreating chamber 18 during rotation of the drum 16. More specifically,the balance ring 38 may be coupled with the rotating drum 16 andconfigured to compensate for a dynamic imbalance during rotation of therotatable drum 16. The balancing material may be in the form of balls,fluid, or a combination thereof. The balance ring 38 may extendcircumferentially around a periphery of the drum 16 and may be locatedat any desired location along an axis of rotation of the drum 16. Whenmultiple balance rings 38 are present, they may be equally spaced alongthe axis of rotation of the drum 16. For example, in the illustratedexample a plurality of balance rings 38 are included in the washingmachine 10 and the plurality of balance rings 38 are operably coupledwith opposite ends of the rotatable drum 16.

The washing machine 10 may further include a liquid supply system forsupplying water to the washing machine 10 for use in treating laundryduring a cycle of operation. The liquid supply system may include asource of water, such as a household water supply 40, which may includeseparate valves 42 and 44 for controlling the flow of hot and coldwater, respectively. Water may be supplied through an inlet conduit 46directly to the tub 14 by controlling first and second divertermechanisms 48 and 50, respectively. The diverter mechanisms 48, 50 maybe a diverter valve having two outlets such that the diverter mechanisms48, 50 may selectively direct a flow of liquid to one or both of twoflow paths. Water from the household water supply 40 may flow throughthe inlet conduit 46 to the first diverter mechanism 48 which may directthe flow of liquid to a supply conduit 52. The second diverter mechanism50 on the supply conduit 52 may direct the flow of liquid to a tuboutlet conduit 54 which may be provided with a spray nozzle 56configured to spray the flow of liquid into the tub 14. In this manner,water from the household water supply 40 may be supplied directly to thetub 14.

The washing machine 10 may also be provided with a dispensing system fordispensing treating chemistry to the treating chamber 18 for use intreating the laundry according to a cycle of operation. The dispensingsystem may include a dispenser 62 which may be a single use dispenser, abulk dispenser or a combination of a single use and bulk dispenser.

Regardless of the type of dispenser used, the dispenser 62 may beconfigured to dispense a treating chemistry directly to the tub 14 ormixed with water from the liquid supply system through a dispensingoutlet conduit 64. The dispensing outlet conduit 64 may include adispensing nozzle 66 configured to dispense the treating chemistry intothe tub 14 in a desired pattern and under a desired amount of pressure.For example, the dispensing nozzle 66 may be configured to dispense aflow or stream of treating chemistry into the tub 14 by gravity, i.e. anon-pressurized stream. Water may be supplied to the dispenser 62 fromthe supply conduit 52 by directing the diverter mechanism 50 to directthe flow of water to a dispensing supply conduit 68.

Non-limiting examples of treating chemistries that may be dispensed bythe dispensing system during a cycle of operation include one or more ofthe following: water, enzymes, fragrances, stiffness/sizing agents,wrinkle releasers/reducers, softeners, antistatic or electrostaticagents, stain repellants, water repellants, energy reduction/extractionaids, antibacterial agents, medicinal agents, vitamins, moisturizers,shrinkage inhibitors, and color fidelity agents, and combinationsthereof.

The washing machine 10 may also include a recirculation and drain systemfor recirculating liquid within the laundry holding system and drainingliquid from the washing machine 10. Liquid supplied to the tub 14through the tub outlet conduit 54 and/or the dispensing supply conduit68 typically enters a space between the tub 14 and the drum 16 and mayflow by gravity to a sump 70 formed in part by a lower portion of thetub 14. The sump 70 may also be formed by a sump conduit 72 that mayfluidly couple the lower portion of the tub 14 to a pump 74. The pump 74may direct liquid to a drain conduit 76, which may drain the liquid fromthe washing machine 10, or to a recirculation conduit 78, which mayterminate at a recirculation inlet 80. The recirculation inlet 80 maydirect the liquid from the recirculation conduit 78 into the drum 16.The recirculation inlet 80 may introduce the liquid into the drum 16 inany suitable manner, such as by spraying, dripping, or providing asteady flow of liquid. In this manner, liquid provided to the tub 14,with or without treating chemistry may be recirculated into the treatingchamber 18 for treating the laundry within.

The liquid supply and/or recirculation and drain system may be providedwith a heating system which may include one or more devices for heatinglaundry and/or liquid supplied to the tub 14, such as a steam generator82 and/or a sump heater 84. Liquid from the household water supply 40may be provided to the steam generator 82 through the inlet conduit 46by controlling the first diverter mechanism 48 to direct the flow ofliquid to a steam supply conduit 86. Steam generated by the steamgenerator 82 may be supplied to the tub 14 through a steam outletconduit 87. The steam generator 82 may be any suitable type of steamgenerator such as a flow through steam generator or a tank-type steamgenerator. Alternatively, the sump heater 84 may be used to generatesteam in place of or in addition to the steam generator 82. In additionor alternatively to generating steam, the steam generator 82 and/or sumpheater 84 may be used to heat the laundry and/or liquid within the tub14 as part of a cycle of operation.

Additionally, the liquid supply and recirculation and drain system maydiffer from the configuration shown in FIG. 1, such as by inclusion ofother valves, conduits, treating chemistry dispensers, sensors, such aswater level sensors and temperature sensors, and the like, to controlthe flow of liquid through the washing machine 10 and for theintroduction of more than one type of treating chemistry.

The washing machine 10 also includes a drive system for rotating thedrum 16 within the tub 14. The drive system may include a motor 88 forrotationally driving the drum 16. The motor 88 may be directly coupledwith the drum 16 through a drive shaft 90 to rotate the drum 16 about arotational axis during a cycle of operation. The motor 88 may be abrushless permanent magnet (BPM) motor having a stator 92 and a rotor94. Alternately, the motor 88 may be coupled with the drum 16 through abelt and a drive shaft to rotate the drum 16, as is known in the art.Other motors, such as an induction motor or a permanent split capacitor(PSC) motor, may also be used. The motor 88 may rotationally drive thedrum 16 including that the motor 88 may rotate the drum 16 at variousspeeds in either rotational direction.

The washing machine 10 also includes a control system for controllingthe operation of the washing machine 10 to implement one or more cyclesof operation. The control system may include a controller 96 locatedwithin the cabinet 12 and a user interface 98 that may be operablycoupled with the controller 96. The user interface 98 may include one ormore knobs, dials, switches, displays, touch screens and the like forcommunicating with the user, such as to receive input and provideoutput. The user may enter different types of information including,without limitation, cycle selection and cycle parameters, such as cycleoptions.

The controller 96 may include the machine controller and any additionalcontrollers provided for controlling any of the components of thewashing machine 10. For example, the controller 96 may include themachine controller and a motor controller. Many known types ofcontrollers may be used for the controller 96. It is contemplated thatthe controller may be a microprocessor-based controller that implementscontrol software and sends/receives one or more electrical signalsto/from each of the various working components to effect the controlsoftware. As an example, proportional control (P), proportional integralcontrol (PI), and proportional derivative control (PD), or a combinationthereof, a proportional integral derivative control (PID control), maybe used to control the various components.

As illustrated in FIG. 2, the controller 96 may be provided with amemory 100 and a central processing unit (CPU) 102. The memory 100 maybe used for storing the control software that may be executed by the CPU102 in completing a cycle of operation using the washing machine 10 andany additional software. Examples, without limitation, of cycles ofoperation include: wash, heavy duty wash, delicate wash, quick wash,pre-wash, refresh, rinse only, and timed wash. The memory 100 may alsobe used to store information, such as a database or table, and to storedata received from one or more components of the washing machine 10 thatmay be communicably coupled with the controller 96. The database ortable may be used to store the various operating parameters for the oneor more cycles of operation, including factory default values for theoperating parameters and any adjustments to them by the control systemor by user input.

The controller 96 may be operably coupled with one or more components ofthe washing machine 10 for communicating with and controlling theoperation of the component to complete a cycle of operation. Forexample, the controller 96 may be operably coupled with the motor 88,the pump 74, the dispenser 62, the steam generator 82, and the sumpheater 84 to control the operation of these and other components toimplement one or more of the cycles of operation.

The controller 96 may also be coupled with one or more sensors 104provided in one or more of the systems of the washing machine 10 toreceive input from the sensors, which are known in the art and not shownfor simplicity. Non-limiting examples of sensors 104 that may becommunicably coupled with the controller 96 include: a treating chambertemperature sensor, a moisture sensor, a weight sensor, a chemicalsensor, a position sensor, an imbalance sensor, a load size sensor, anda motor torque sensor, which may be used to determine a variety ofsystem and laundry characteristics, such as laundry load inertia, mass,and imbalance magnitude.

A typical cycle of operation generally includes multiple phasesdepending on the intended purpose of the cycle. For example, aconventional wash cycle of operation includes at least three phases: awash phase, a rinse phase, and an extraction phase (also referred to asspin phase). These three wash cycle phases may be supplemented byadditional phases, such as a pre-treatment or a stain removal phase, forexample, based on the selected cycle of operation. Optionally, one ormore of the phases may be repeated, such as the rinse phase. In general,during the wash phase, the laundry load is treated with a liquid thatincludes a treating chemistry to facilitate removing soil and stainsfrom the laundry. During the rinse phase, water is supplied to thelaundry load to remove residual treating chemistry and/or soil, asdesired. The extraction phase includes rotating the laundry load at highspeeds to extract liquid from the laundry load prior to the end of thecycle. Removal of liquid from the laundry load at the end of the washcycle can decrease the amount of energy and/or time required to dry thelaundry load after completion of the laundry load.

The washing machine 10 may extract liquid from the laundry items locatedwithin the treating chamber 18 forming the laundry load during a cycleof operation by rotating the drum 16 about the drum rotational axis suchthat inertia causes liquid to be extracted from the laundry items.Extraction rotation speeds, also referred to as spin speeds, aretypically high in order to extract the desired amount of liquid from thelaundry items in a short amount of time, thus saving time and energy.However, when the laundry items and liquid are not evenly distributedabout the rotational axis of the drum 16 and/or unevenly distributedabout the circumference of the drum, an imbalance condition may occur.

Typical spin speeds in a horizontal axis washer are about 800-2000 RPMand provide an inertial force of 1 G or greater, sometimes even up toand greater than 400 G, to the laundry items. At such high speeds, animbalance can result in unacceptable vibratory movement of the tub 14,the drum 16, and even the entire washing machine 10. The washing machine10 can be affected severely enough that it may exhibit a side-to-sidemovement, when viewed from the front/rear, which results in a “walking”across the floor and cause floor vibration. The tub 14 can move enoughsuch that the tub 14 reaches the limit of its suspension and/or contactsthe surrounding cabinet 12, referred to as “cabinet hits,” withconsequent noise and possible damage. In addition, the imbalance canalso cause the drum 16 to move relative to the tub 14 to such an extentthat the drum 16 contacts the surrounding tub 14, with consequent noiseand possible damage.

As used herein, rotating the drum 16 at an extraction speed, referred tointerchangeably as a spin speed, refers to rotating the drum 16 to applyan inertial force of greater than or equal to 1 G to at least some ofthe laundry items. Spin speeds are high rotation speeds that result inthe laundry items being held by inertial force against the inner surfaceof the drum 16 as the drum 16 rotates, also sometimes referred to as asatellizing or plastering condition. For a horizontal axis washingmachine 10, the drum 16 may rotate about an axis that may be inclinedrelative to the horizontal, in which case the term “1 G” refers to thevertical component of the inertial force vector, and the total magnitudealong the inertial force vector would therefore be greater than 1 G.

As described herein, the term “imbalance” or “unbalance,” when usedalone or in combination with the words “condition,” “mass,” “phase,”“magnitude,” “position,” or otherwise, refers to an object being in astate of unbalance relative to its respective reference frame, i.e., anobject positioned in a washing machine so as to shift the center ofgravity, or the orientation of the principal axis, of a rotatinginertial mass away from the longitudinal axis of the rotating shaft inthe washing machine.

Generally, an extraction phase involves rotating the drum 16 at a finalspin or extraction speed for a predetermined period of time to extractat least a portion of the liquid carried by the laundry, after which thedrum speed is decreased and the extraction phase is ended. The finalspin speed is often a maximum allowable speed for rotating the drum 16based on a predetermined set of conditions, such as the size of thelaundry load and/or an amount of unbalance in the load, for example. Theextraction phase can include multiple sections or sub-phases leading upto rotating the drum 16 at the maximum allowable spin speed to extractliquid from the laundry load. For example, the extraction phase canoptionally include a tumbling section in which the drum 16 isalternately rotated clockwise and counterclockwise at slow speeds, lessthan a spin speed, to facilitate distribution of the laundry load. Inanother example, the extraction phase can include an imbalance magnitudedetection section in which a magnitude of imbalance of the laundry loadis determined before the laundry is rotated at a spin speed to extractliquid. The tumbling and imbalance magnitude detection sections mayoptionally be considered separate phases, independent of the extractionphase.

Referring now to FIG. 3, a flow chart of a method 200 for operating alaundry treating appliance, such as the washing machine 10, isillustrated. The sequence depicted for this method is for illustrativepurposes only, and is not meant to limit the method in any way as it isunderstood that the steps may proceed in a different logical order oradditional or intervening steps may be included without detracting fromthe present disclosure.

One manner in which the likelihood of unacceptable vibratory movementsof the tub 14, the drum 16, and/or other components of the washingmachine 10 can be decreased during an extraction phase is to limit thespeed at which the drum 16 is rotated based upon a magnitude ofimbalance of the laundry load. The method 200 can be used to determine amaximum allowable spin speed for rotating the laundry load during anextraction phase to extract liquid from the laundry based on inputting amagnitude of imbalance of the laundry load prior to spinning at a spinspeed into an algorithm that includes at least one non-linear polynomialfunction.

The method 200 begins assuming that a user has placed laundry items tobe treated into the treating chamber 18 and selected a cycle ofoperation through the user interface 98. The method 200 may be used withany cycle of operation that includes wetting the laundry load withliquid, non-limiting examples of which include a wash cycle, a rinsecycle, and a treatment aid cycle. At 202, the controller 96 initiatesthe selected cycle of operation and controls the liquid supply systemand the dispensing system to wet the laundry items with water and/or atreating chemistry according to the selected cycle of operation at 204.At 206, the drum 16 may be rotated according the selected cycle ofoperation to facilitate wetting the laundry items with water and/or adispensed treating chemistry. The wetting of the laundry items androtating the drum at 204 and 206 may be implemented one or more timesbased on the selected cycle of operation as part of a liquid treatingphase 207. In one example, the wetting of the laundry items and rotatingthe drum at 204 and 206 occurs at least once as part of a pre-washphase, a wash phase and/or a rinse phase of the selected cycle ofoperation. In another example, the wetting of the laundry items androtating the drum at 204 and 206 occurs as part of a treatment aid phasein which the laundry items are treated with a treatment aid,non-limiting examples of which include a whitening agent, a stainremoval agent, and an anti-wrinkle agent.

Following the liquid treating phase 207, an extraction phase 208 may beimplemented to remove at least a portion of the liquid supplied duringthe liquid treating phase 207 and carried by the laundry load. Prior toincreasing the drum speed to a maximum allowable spin speed in theextraction phase 208, a magnitude of imbalance of the laundry load maybe determined at 210 according to any suitable method known in the art.Non-limiting exemplary methods for determining the magnitude ofimbalance include those disclosed in U.S. Pub. No. 2013/0000053,published Jan. 3, 2013, and entitled “Laundry Treating Appliance withMethod to Reduce Drum Excursions,” which is incorporated herein byreference in its entirety. Another exemplary method for determining themagnitude of imbalance includes determining a magnitude of imbalancebased on changing forces experienced by the motor during rotation of thedrum 16. While determining the magnitude of imbalance at 210 isdescribed in the context of being part of the extraction phase 208, thedetermination of the magnitude of imbalance at 210 may be considered asa separate phase, distinct from the extraction phase 208.

The magnitude of imbalance determined at 210 can be used at 212 todetermine a maximum allowable extraction speed for rotating the drumduring the extraction phase 208 to extract at least a portion of theliquid carried by the laundry load. An extraction speed algorithm can bestored in the memory 100 for determining the maximum extraction speedbased on the magnitude of imbalance output at 210. The extraction speedalgorithm can include one or more functions configured to receive themagnitude of imbalance determined at 210 as input and provide an outputindicative of the maximum allowable extraction speed. The controller 96can be configured to control the motor 88 to rotate the drum 16 at themaximum allowable extraction speed at 214 based on the output from 212.

The extraction speed algorithm includes at least one non-linearpolynomial function configured to receive the magnitude of imbalancedetermined at 210 as input and provide an output indicative of themaximum allowable extraction speed at which the drum 16 is to be rotatedto extract liquid from the laundry load. It will be understood that whenthe extraction speed algorithm includes a single function, that singlefunction is a non-linear polynomial function. When the extraction speedalgorithm includes more than one function, at least one of the functionsis a non-linear polynomial function, however, the additional functionsmay be a linear function, a non-linear polynomial function, anexponential function, or any other type of function. The one or morefunctions of the extraction speed algorithm provide a unique outputindicative of a unique maximum allowable extraction speed for eachmagnitude of imbalance determined at 210.

The drum 16 can be rotated at the maximum allowable extraction speed at214 for a predetermined period of time or until one or morecharacteristics of the laundry load is satisfied. For example, the drum16 can be rotated at 214 for a predetermined period of time based on anamount of laundry, the selected cycle of operation, a selected degree ofdryness of the load, and/or selected maximum time for the selected cycleof operation. In another example, the drum 16 can be rotated at 214until a predetermined amount of liquid has been extracted from thelaundry. In another example, the drum 16 can be rotated at 214 until aremaining moisture content (RMC) of the laundry satisfies apredetermined RMC threshold. The term “satisfies” the threshold is usedherein to mean that the variation satisfies the predetermined threshold,such as being equal to, less than, or greater than the threshold value.It will be understood that such a determination may easily be altered tobe satisfied by a positive/negative comparison or a true/falsecomparison. For example, a less than threshold value can easily besatisfied by applying a greater than test when the data is numericallyinverted. One example of determining the RMC during the extraction phasemay be based on the methods disclosed in U.S. application Ser. No.15/606,188, entitled “Laundry Treating Appliance and Method ofOperation,” filed on May 26, 2017, now U.S. Pat. No. 10,501,880, issuedon Dec. 10, 2019, which is herein incorporated by reference in itsentirety.

At 216, the cycle of operation can be completed subsequent to spinningthe drum 16 at the maximum allowable extraction speed. The cycle ofoperation can be completed by rotating the drum 16 at a speed less thanthe maximum allowable extraction speed, which can include activelybraking the drum 16 and/or allowing the drum 16 to coast to a lowerspeed of rotation. Completion of the cycle of operation optionallyincludes treatment of the laundry with one or more treatment aids,non-limiting examples of which include fragrances, anti-wrinkle agents,anti-shrinkage agents, leave-in fabric softeners, and color protectors.Prior to ending the cycle of operation at 216, the liquid treating phase207 and the extraction phase 208 can be repeated one or more times basedon the selected cycle of operation.

Referring now to FIGS. 4 and 5, the functions used in the extractionspeed algorithm utilized in the method 200 of FIG. 3 can be obtained byanalyzing data relating imbalance magnitude and an acceptable maximumallowable extraction speed using regression analysis. The data 250 and260 in FIGS. 4 and 5 is not necessarily indicative of real data and isprovided for the purposes of illustration only. The one or morefunctions of the extraction speed algorithm relate the magnitude ofimbalance to a maximum allowable extraction speed over a range ofimbalance magnitudes. The functions may be determined based on empiricaland/or theoretical data relating a magnitude of imbalance with anacceptable maximum allowable extraction speed. In one example, a maximumallowable extraction speed may be determined experimentally based ontest loads having a known magnitude of imbalance. The maximum allowableextraction speed may be based on a maximum speed that the drum can berotated for a given imbalance magnitude such that operation of thewashing machine 10 satisfies a predetermined acceptable or safeoperating condition. The maximum allowable extraction speed thatsatisfies the predetermined safe operating condition may be based on anysuitable criteria, non-limiting examples of which include a speed atwhich cabinet hits during spinning satisfy a predetermined threshold, aspeed at which a noise level during spinning satisfy a predeterminedthreshold, and/or a percentage of the maximum allowable speed accordingto any suitable criteria.

The maximum allowable extraction speed may be determined experimentallyfor each model of washing machine 10 or the data from one or moredifferent models may be used to extrapolate the maximum allowableextraction speed for a given imbalance magnitude to different models.The maximum allowable extraction speed may be determined over an entirerange of imbalance magnitudes of interest or the maximum allowableextraction speed may be extrapolated from a sub-set of imbalancemagnitudes within the range of interest.

Referring to FIG. 4, a range of data points 250 relating a maximumallowable extraction speed (in rotations per minute, RPM) to aparticular imbalance magnitude for an exemplary washing machine isshown. At least some of the data points 250 are obtained experimentally.Optionally, some of the data points 250 may be estimates based onempirical data. The data 250 in FIG. 4 may be analyzed using regressionanalysis to provide one or more functions that model the data 250 tosatisfy a predetermined degree of fit.

As illustrated in FIG. 4, the data 250 in FIG. 4 can be modeled usingtwo functions, Function 1 and Function 2. Function 1 is a non-linearpolynomial function that models the data between data point A and datapoint B; Function 2 is a linear function that models the remaining data250 between data point B and data point C. The data 250 in FIG. 4 can bemodeled using one or more functions that provides the highest degree offit and/or a fit that satisfies a minimum fit threshold. The degree offit can be determined according to any suitable analysis, a non-limitingexample of which includes R-squared analysis. In one example, the numberof functions used to model the data may be based on minimizing the useof functions having variables multiplied to powers greater than 4,optionally greater than 3. In another example, the functions used tomodel the data may be based on avoiding functions with little to noslope (i.e. functions with outputs that do not change much as thevariable inputs change). In still another example, the data may bemodeled using the minimum number of functions. Modeling the data may bebased on any combination of these considerations and/or any additionalconsiderations.

FIG. 5 illustrates a range of data points 260 relating a maximumallowable extraction speed to an imbalance magnitude for anotherexemplary washing machine different from that of FIG. 4. The data 260 inFIG. 5 can be modeled using three functions—Function 1, Function 2, andFunction 3. Function 1 is a linear function that models the data 260between data point A and data point B; Function 2 is a non-linearpolynomial function that models the data between data point B and datapoint C; Function 3 is a non-linear polynomial function that models thedata between data point C and D. The data 260 in FIG. 5 can be modeledusing one or more functions that provides the highest degree of fitand/or a fit that satisfies a minimum fit threshold. The degree of fitcan be determined according to any suitable analysis, a non-limitingexample of which includes R-squared analysis.

The functions illustrated in FIGS. 4 and 5 can be utilized in theextraction speed algorithm for each particular washing machine in orderto determine the maximum allowable extraction speed. Modeling the datausing regression analysis provides a function that allows a uniquemaximum allowable spin speed to be determined for each unique input ofimbalance magnitude. In this manner, the maximum allowable spin speedcan be tailored according to the specific imbalance magnitude, which mayprovide benefits relating to time, energy, and/or amount of liquidextracted during an extraction phase.

FIG. 6 illustrates an exemplary method 300 for determining the maximumallowable extraction speed at 212 of the method 200 of FIG. 3 using anextraction speed algorithm based on the exemplary data 250 of FIG. 4.While the method 300 is illustrated for use with the method 200 of FIG.3, it is also contemplated that the method 300 may be utilized withalternative methods that include an extraction phase.

The method 300 includes decision making processes 302, 306, and 312 inwhich the imbalance magnitude is compared to predetermined thresholdsthat are based on the ranges of imbalance magnitude corresponding toeach function used in the extraction speed algorithm. In the presentexample based on the exemplary data 250 of FIG. 4, each threshold A, B,and C of decision making process 302, 306, and 312 corresponds to thedata points A, B, and C of FIG. 4 defining the limits of each functionused to model the data 250.

The controller 96 is programmed to analyze the imbalance magnitudedetermined at 210 and determine if the imbalance magnitude satisfies afirst threshold A at 302. If the imbalance magnitude satisfies the firstthreshold A, then controller 96 controls the motor 88 to rotate the drum16 at a predetermined maximum speed at 304. Satisfying a threshold caninclude the imbalance magnitude being less than the threshold value, asillustrated, or may include being less than or equal to the thresholdvalue. The controller 96 can then proceed to process 214 of the method200 of FIG. 3 to rotate the drum 16 at the maximum speed and completethe cycle of operation at 216. In one example, the first threshold A maycorrespond to an imbalance magnitude that is low enough such that it isacceptable to rotate the drum 16 at the highest allowable speed.

If the imbalance magnitude does not satisfy the first threshold A, theprocess proceeds to 306 to determine whether the imbalance magnitudesatisfies a second threshold B. If the imbalance magnitude satisfies thesecond threshold B, the imbalance magnitude is input into Function 1 ofFIG. 4 at 308. The output from Function 1 is used to determine a maximumallowable extraction speed to rotate the drum 16 during the extractionphase. At 310 the controller 96 controls the motor 88 to rotate the drum16 at the maximum allowable extraction speed determined from the outputfrom Function 1 at 308. The controller 96 can then proceed to process214 of the method 200 of FIG. 3 to complete the cycle of operation.

If the imbalance magnitude does not satisfy the second threshold B, theprocess proceeds to 312 to determine whether the imbalance magnitudesatisfies a third threshold C. If the imbalance magnitude satisfies thethird threshold C, the imbalance magnitude is input into Function 2 ofFIG. 4 at 314. The output from Function 2 is used to determine a maximumallowable extraction speed to rotate the drum 16 during the extractionphase. At 316, the controller 96 controls the motor 88 to rotate thedrum 16 at the maximum allowable spin speed determined from the outputfrom Function 2 at 314. The controller 96 can then proceed to process214 of the method 200 of FIG. 3 to complete the cycle of operation.

If the imbalance magnitude does not satisfy the third threshold C, at318 the drum 16 may be rotated according to a minimum spin speed or aredistribution cycle may be initiated to decrease the imbalancemagnitude. If a redistribution cycle is initiated, the method 300 may berepeated in order to determine the maximum allowable extraction speed.Additional decision making processes 302, 306, 312 can be implementedbased on the number of functions utilized by the extraction speedalgorithm. For example, the method 300 based on the exemplary data 260of FIG. 5 would include a 4^(th) decision making process, subsequent tothe decision making process 312. Each of the thresholds A, B, and, C ofprocesses 302, 306, and 312 can be based on the range of imbalancemagnitudes for each function utilized in the extraction speed algorithm.

The aspects described above can provide a variety of benefits inimplementing a cycle of operation that includes an extraction phase toremove liquid from laundry. The extraction speed algorithm describedherein can be used to provide a unique output indicative of a uniquemaximum allowable extraction speed for each magnitude of imbalance. Thisallows the drum to be rotated at a maximum extraction speed that isspecifically suitable for that magnitude of imbalance. Increasedextraction speeds can facilitate extracting liquid from the laundry at agreater rate, thus decreasing the amount of time required during theextraction phase to extract a predetermined amount of liquid and/orincreasing the amount of liquid extracted within a given time period.Shorter extraction phases can decrease cycle time, which can increaseconvenience for the user and optionally use less energy. Decreasing theamount of liquid carried by the laundry when the extraction phase iscomplete can also decrease the time and/or energy required to dry thelaundry, which may be convenient for the user and optionally be morecost effective.

Conventional washing machines will often utilize a look-up table thatdetermines a single discrete maximum allowable extraction speed based onpredetermined ranges of imbalance magnitude. For example, a conventionalwashing machine may include a look-up table that sets the maximumallowable extraction speed to 100 G when the imbalance magnitude is 0 to10, 75 G when the imbalance magnitude is 11-20, and 50 G when theimbalance magnitude is 21-30. In this example, an imbalance magnitude of21 would result in a maximum allowable extraction speed of 50 G. Becauseit is close to the next range, it may actually be acceptable to rotatethe drum at the higher extraction speed of 75 G. However, because thereis only a single discrete maximum allowable extraction speed for eachrange, the drum will be rotated at the slower speed, possibly forgoingone or more of benefits associated with rotating the drum at higherspeeds discussed above.

In contrast, the methods described herein utilizing the extraction speedalgorithm provide a unique output indicative of a unique maximumallowable extraction speed for each magnitude of imbalance, thusallowing the extraction phase to be tailored to the specific conditionsof that particular laundry load. The use of non-linear polynomials tomodel the data of extraction speed based on imbalance magnitude canimprove the estimation of a maximum allowable extraction speed that canbe reached while still satisfying the predetermined safe operatingconditions of the washing machine. Poor modeling may result in rotatingat an extraction speed that causes undesirable operating conditions,such as undesirable vibrations and/or noises during the extractionphase.

As can be seen in the exemplary data of FIGS. 4 and 5, the relationshipbetween a maximum allowable extraction speed for a given imbalancemagnitude is not consistent throughout the range of imbalance magnitudesthat may be encountered. Modeling the data using multiple functions,including at least one non-linear polynomial function, can improve theestimation of a maximum allowable extraction speed that satisfies thepredetermined operating conditions of the washing machine over the rangeof imbalance magnitudes that may be encountered and can decrease thelikelihood of an extraction speed that results in undesirableconditions.

Referring now to FIG. 7, a method 400 for controlling the speed ofrotation of the drum 16 during the extraction phase 208 is illustrated.While the method 400 is described in the context of the method 200 ofFIG. 3, it is contemplated that the method 400 can be used withalternative methods that include an extraction phase.

The method 400 can be used to update the maximum allowable extractionspeed during the extraction phase 208 after the drum 16 is rotated atthe maximum allowable extraction speed at 214, which in this scenariocan be referred to as an initial maximum allowable extraction speed. Themethod 400 utilizes information stored in the memory 100 of thecontroller 96 related to a stored maximum rotation speed (“Top RPM”) 402for the washing machine 10, a stored power limit 404 for the motor 88,and a starting Advance Count 406. The Top RPM 402 may be based on one ormore factors, non-limiting examples of which include characteristics ofthe drum 16, tub 14, and suspension system 28, characteristics of themotor 88, and an amount of laundry present in the drum 16.

At 408, the controller 96 determines whether the initial maximumallowable extraction speed determined at 212 of the method of FIG. 3 (“BRPM”) is less than the Top RPM. If the maximum allowable extractionspeed B RPM is not less than the Top RPM, then the method proceeds toprocess 410 in which the motor power output is monitored and theextraction speed is controlled to maintain a predetermined safeoperating condition. In the example of 410, the safe operating conditionis based on operating the motor 88 at a power level that is not greaterthan a predetermined percentage of the maximum power limit 404 of themotor 88. The predetermined percentage may be 100% of the maximum powerlimit 404 or some percentage greater than or less than 100%. Asillustrated in FIG. 7, the safe operating condition is set to 1.05 timesthe maximum power limit 404.

At 412, the controller 96 determines whether the current motor poweroutput satisfies a first power threshold, such as 1.05 times the powerlimit. If the current motor power output satisfies the first powerthreshold at 412, then the process 410 is implemented to decrease therotation speed of the drum 16 and thus decrease the power output of themotor 88. The process 410 can be repeated multiple times toincrementally decrease the rotation speed of the drum 16 until thecurrent motor power output at 412 no longer satisfies the first powerthreshold.

If the current motor power output does not satisfy the first powerthreshold at 412, then at 420 it is determined whether the extractionphase is complete. In the example of FIG. 7, completion of theextraction phase is based on a predetermined time period. However, it iscontemplated that completion of the extraction phase may be based on anysuitable criteria, non-limiting examples of which include an amount ofliquid extracted, a remaining moisture content of the laundry, and arate of liquid extracted from the laundry. If the predetermined timeperiod at 420 is satisfied, then the method 400 proceeds to 216 of themethod 200 of FIG. 3 to complete the selected cycle of operation.

If the predetermined time period at 420 is not satisfied, then process422 is implemented to continue rotating the drum 16 during theextraction phase. The process 422 includes monitoring the motor power at424 to determine whether the current motor power satisfies a secondpower threshold. The second power threshold can be a predeterminedpercentage of the motor power limit, such as the example of 0.97 timesthe motor power limit 404 of FIG. 7. The second power threshold at 424in combination with the first power threshold at 412 defines a motorpower range within which it is acceptable for the motor 88 to beoperated during rotation of the drum 16 at an extraction speed duringthe extraction phase.

During the extraction phase in which the drum 16 is being rotated athigh speeds and liquid is being extracted from the laundry load, thecharacteristics of the laundry load can change. For example, as liquidis extracted from the laundry load, a mass of the laundry load maychange and/or a distribution of laundry within the drum 16 may change.In another example, an imbalance magnitude or a position of an imbalancemay change as liquid is extracted. Cycling between processes 410 and 422allows the drum to be rotated at the initial maximum allowable spinspeed as long as the motor power remains within an acceptable range, asdefined by the first and second power thresholds at 412 and 424.

Process 410 provides a method by which the initial maximum allowablespin speed can be incrementally decreased if needed to maintain themotor power within the acceptable range defined by the first and secondpower thresholds 412 and 424. If the motor power never satisfies thefirst power threshold at 412, the drum 16 will continue to be rotated atthe initial maximum allowable spin speed according to the cycle ofoperation. If a characteristic of the laundry load changes such that themotor power does satisfy the first power threshold at 412, the process410 can be used to rotate the drum 16 at a new maximum allowable spinspeed that results in the motor power not satisfying the first powerthreshold at 412.

Still referring to FIG. 7, an additional process 430 can be included inthe method 400 to take advantage of the changing characteristics of thelaundry load during the extraction phase to improve liquid extractionfrom the laundry load by increasing the maximum allowable spin speed toa new, higher maximum allowable spin speed, if conditions allow. Asillustrated in FIG. 7, when the current motor power at 424 satisfies thesecond power threshold, the method advances to process 430 where thecurrent maximum allowable speed B RPM can be incrementally increased at432. The process 430 can be coupled with decision making at 408 suchthat processes 410 and 422 can be implemented to maintain the motorpower within the limits defined by the first and second power thresholdsat 412 and 424 and process 430 can be implemented to increase themaximum allowable spin speed from the current speed.

Process 430 can optionally be configured to incrementally increase theextraction speed only when the motor power satisfies the second powerthreshold at 424 a predetermined number of times at 434. For example, asillustrated in FIG. 7, the extraction speed will only be increased ifthe motor power satisfies the second power threshold at 424 apredetermined number of times, such as 10 times (shown). In the exampleillustrated in FIG. 7, the number of increases is limited to 10,although the limit may be set to any suitable number. The count decisionat 434 may minimize effect of rapid changes in the laundry load as aresult of transient laundry load conditions. Process 430 can optionallyinclude a count decision at 434 such that the process 430 is limited tobe implemented a predetermined number of times. In this manner, thenumber of times and/or the total amount of increase in the extractionspeed during the extraction phase can be limited. For example, asillustrated in FIG. 7, the extraction speed will only be increased ifthe previous number of increases satisfies a predetermined number. Inthe example illustrated in FIG. 7, the number of increases is limited to9, although the limit may be set to any suitable number.

As discussed above, as liquid is removed from the laundry load, one ormore characteristics of the laundry may change, resulting in a newlaundry load condition that is different from the condition during whichthe initial maximum allowable spin speed was determined at 212 of themethod 200 of FIG. 3. The new condition may provide an opportunity torotate the drum at a higher extraction speed, which may increase theefficiency of liquid extraction from the laundry load. Rotating at ahigher extraction speed can potentially decrease cycle time and/orincrease the efficiency of liquid extraction for a given cycle ofoperation.

For example, rotating at a higher extraction speed can extract moreliquid from the laundry within a predetermined period of time, i.e. therate of extraction may increase. Thus, the amount of liquid extractedwithin a predetermined period of time may increase, which may result inless energy used in a subsequent drying process. In another example, therate of extraction can result in the laundry satisfying a givencondition, such as a predetermined remaining moisture content, in lesstime, which may provide time and/or energy benefits. The process 430provides an opportunity to increase the maximum allowable extractionspeed during extraction based on changing conditions of the laundryload, even in situations in which the extraction speed may have beenpreviously decreased according to process 410.

To the extent not already described, the different features andstructures of the various embodiments may be used in combination witheach other as desired. That one feature may not be illustrated in all ofthe embodiments is not meant to be construed that it may not be, but isdone for brevity of description. Thus, the various features of thedifferent embodiments may be mixed and matched as desired to form newembodiments, whether or not the new embodiments are expressly described.For example, the features of the methods 200, 300, and/or 400, can becombined to make new methods, not explicitly described, or combined withadditional methods without deviated from the scope of the invention.

While the invention has been specifically described in connection withcertain specific embodiments thereof, it is to be understood that thisis by way of illustration and not of limitation. Reasonable variationand modification are possible within the scope of the forgoingdisclosure and drawings without departing from the spirit of theinvention which is defined in the appended claims.

What is claimed is:
 1. A laundry treating appliance, comprising: a drumat least partially defining a treating chamber for receiving a laundryload for treatment according to a cycle of operation and rotatable aboutan axis of rotation; a liquid supply system fluidly coupled with thetreating chamber for supplying liquid to the laundry load to wet thelaundry load according to at least one of a wash phase or a rinse phaseof a selected cycle of operation; a motor operably coupled with the drumand configured to rotate the drum according to the cycle of operation;and a controller operably coupled to the motor and configured to controlthe motor to rotate the drum, the controller configured to: determine amagnitude of imbalance of a wetted laundry load based on based on atleast one characteristic of the motor as output from the motor or asensor operably coupled thereto; provide the magnitude of imbalance asinput into an algorithm, comprising at least one non-linear polynomialfunction that provides an output indicative of a first extraction speedto the algorithm based on the input; and control the motor to rotate thedrum at the first extraction speed to extract at least a portion of theliquid carried by the wetted laundry load.
 2. The laundry treatingappliance of claim 1 wherein the controller is configured to determine,during a rotating of the drum at the first extraction speed, a poweroutput of the motor.
 3. The laundry treating appliance of claim 2wherein the controller is configured to rotate the drum at a secondextraction speed, greater than the first extraction speed, when thepower output of the motor is less than a predetermined power limit ofthe motor.
 4. The laundry treating appliance of claim 1 wherein thealgorithm provides a unique output indicative of a first uniqueextraction speed for each unique input.
 5. The laundry treatingappliance of claim 1 wherein the algorithm comprises the at least onenon-linear polynomial function, which defines a first non-linearpolynomial function and a second function, different than the firstnon-linear polynomial function, wherein the controller is configured to:when the magnitude of imbalance satisfies a first threshold, provide themagnitude of imbalance as input to the first non-linear polynomialfunction, which provides an output indicative of the first extractionspeed; and when the magnitude of imbalance satisfies a second threshold,provide the magnitude of imbalance as input to the second function,which provides an output indicative of the first extraction speed. 6.The laundry treating appliance of claim 5 wherein the second function isone of a linear function or a non-linear polynomial function.
 7. Thelaundry treating appliance of claim 5 wherein the algorithm furthercomprises a third function, different than the first non-linearpolynomial function and the second function, and wherein the controlleris configured to provide the magnitude of imbalance as input to thethird function when the magnitude of imbalance satisfies a thirdthreshold, wherein the third function provides an output indicative ofthe first extraction speed.
 8. The laundry treating appliance of claim1, further comprising a moisture sensor configured to determine aremaining moisture content and wherein the controller is furtherconfigured to rotate the drum at the first extraction speed until athreshold of a remaining moisture content of the wetted laundry load issatisfied.
 9. The laundry treating appliance of claim 1 wherein thecontroller is further configured to estimate a moisture content of thewetted laundry load to define an estimated remaining moisture contentand further configured to rotate the drum at the first extraction speeduntil a threshold of the estimated remaining moisture content of thewetted laundry load is satisfied.
 10. A laundry treating appliance,comprising: a drum at least partially defining a treating chamber forreceiving a laundry load for treatment according to a cycle of operationand rotatable about an axis of rotation; a liquid supply system fluidlycoupled with the treating chamber for supplying liquid to the laundryload to wet the laundry load according to at least one of a wash phaseor a rinse phase of a selected cycle of operation; a motor operablycoupled with the drum and configured to rotate the drum according to thecycle of operation; a sensor configured to provide an output indicativeof the magnitude of imbalance to the controller; and a controlleroperably coupled to the motor and configured to control the motor torotate the drum, the controller configured to: determine a magnitude ofimbalance of a wetted laundry load based on the sensor output or basedon at least one characteristic of the motor as output from the motor ora sensor operably coupled thereto; provide the magnitude of imbalance asinput into an algorithm, comprising at least one non-linear polynomialfunction that provides an output indicative of a first extraction speedto the algorithm based on the input; and control the motor to rotate thedrum at the first extraction speed to extract at least a portion of theliquid carried by the wetted laundry load.
 11. The laundry treatingappliance of claim 10 wherein the controller is configured to determine,during the rotating of the drum at the first extraction speed, a poweroutput of the motor.
 12. The laundry treating appliance of claim 11wherein the controller is configured to rotate the drum at a secondextraction speed, greater than the first extraction speed, when thepower output of the motor is less than a predetermined power limit ofthe motor.
 13. The laundry treating appliance of claim 10 wherein thealgorithm provides a unique output indicative of a first uniqueextraction speed for each unique input.
 14. The laundry treatingappliance of claim 10 wherein the algorithm comprises the at least onenon-linear polynomial function, which defines a first non-linearpolynomial function and a second function, different than the firstnon-linear polynomial function, wherein the controller is configured to:when the magnitude of imbalance satisfies a first threshold, provide themagnitude of imbalance as input to the first non-linear polynomialfunction, which provides an output indicative of the first extractionspeed; and when the magnitude of imbalance satisfies a second threshold,provide the magnitude of imbalance as input to the second function,which provides an output indicative of the first extraction speed. 15.The laundry treating appliance of claim 14 wherein the second functionis one of a linear function or a non-linear polynomial function.
 16. Thelaundry treating appliance of claim 14 wherein the algorithm furthercomprises a third function, different than the first non-linearpolynomial function and the second function, and wherein the controlleris configured to provide the magnitude of imbalance as input to thethird function when the magnitude of imbalance satisfies a thirdthreshold, wherein the third function provides an output indicative ofthe first extraction speed.
 17. The laundry treating appliance of claim10, further comprising a moisture sensor configured to determine aremaining moisture content and wherein the controller is furtherconfigured to rotate the drum at the first extraction speed until athreshold of a remaining moisture content of the wetted laundry load issatisfied.
 18. The laundry treating appliance of claim 10 wherein thecontroller is further configured to estimate a moisture content of thewetted laundry load to define an estimated remaining moisture contentand further configured to rotate the drum at the first extraction speeduntil a threshold of the estimated remaining moisture content of thewetted laundry load is satisfied.